1. Field of the Invention
The present disclosure relates to a vacuum cleaner. More particularly, the present disclosure relates to a nozzle assembly of a vacuum cleaner, which comes in contact with a surface to be cleaned to draw in dust or dirt with air from the surface to be cleaned.
2. Description of the Related Art
In general, a vacuum cleaner is provided with a nozzle assembly capable of drawing in dust or dirt from a surface to be cleaned. Such a nozzle assembly draws in the dirt or the dust from the surface to be cleaned by a suction force generated form a suction motor mounted in a cleaner body in a state where it comes in contact with the surface to be cleaned.
However, among such conventional nozzle assemblies, a nozzle assembly, which is applied to an upright vacuum cleaner, has a drum brush unit to brush away the dust or dirt stained to the surface to be cleaned, more particularly, a carpet. The nozzle assembly including the drum brush unit is disclosed in Japanese patent publication No. 4132529, German patent publication DE 19602406, and Korean patent publication No. 10-2004-0075569. The disclosed nozzle assembly has a drum brush rotatably joined to a cleaner body, so that it strikes dust or dirt of a surface to be cleaned in an dust inlet thereof to brush away the dust or dirt from the surface to be cleaned. The drum brush is rotated by a motor mounted in the nozzle assembly or by a kinetic energy of drawn-in air. A brush member or blade projected from an outer circumferential surface of the drum brush strikes the surface to be cleaned in a tangential direction while coming in rotation contact therewith. When the drum brush strikes a portion of the surface to be cleaned, which is stained with the dust or dirt, the dust or dirt is scattered while separating from the portion of the surface to be cleaned, and is drawn into the nozzle assembly.
However, dirt, such as hair, fur or the like, which is firmly stuck to the surface to be cleaned, particularly, a surface of carpet, is not separated therefrom well only by the drum brush. Although the drum brush strikes or scrapes against the surface to be cleaned while rotating, scraping strength thereof is too weak to separate the dirt from the surface to be cleaned. If spidery dirt, such as the hair, the fur or the like, is wound on cilia or fibers of the carpet, it is not easily separated from the carpet. In this case, there is an inconvenience in that to clean the carpet, a user should take the spidery dirt off one by one from the carpet, or clean the carpet again by using a cleaning outfit, such as a comb or the like.